Wouldn't you like to see if email you send actually gets read? You can, provided you send it to someone that never messes with their mail client settings.
Did they read it? claims to be able to not only see if your email was viewed, but also record the duration of time the message was viewed as well as the location of the viewer.
I heard of this a few weeks ago. It didn't impress me. Spammers have been including 1 pixel by 1 pixel transparent GIF images hotlinked to a server to see if you viewed their "Grow UR P3N1S... \\//!AGR4 CHEEEP!" emails. This guy lets you do the same. (didn't you always want to be like a spammer?) The Today show seemed impressed, and just had a feature on the service. Slashdot users however, were not impressed (from Sunday, 23 May).
So, here's what you do: Turn off "inline images" in outlook express, or just switch to Mozilla Thunderbird and turn off images in received email. If you use webmail like Yahoo!, you can turn inline images off as well. You should also turn of JavaScript and VBScript in your mail reader, too.
Note that images as an attachment are not a threat. They could still be something from rotten.com, so viewer beware.
